This proposal details the development of ?UroSeqS? as a genetic cytology test to extend the utility of routinely collected urine specimens to the detection of recurrent bladder cancer. UroSeqS is a genetic cytology assay that achieves sensitivity and specificity through identifying DNA mutations causative of cancer from routinely collected clinical specimens. An innovative approach is used toanalyze DNA from routinely collected urine samples with a massively parallel sequencing-based assay and includes a unique processing technique that increases detection sensitivity.